The present study was designed to evaluate the antibacterial activity and safety of sequential extracts of Gymnema sylvestre R.Br. (Gurmar) leaves. Antibacterial activity of chloroformic, hexane, ethanolic and aqueous extracts of Gymnema sylvestre leaves was evaluated against five bacterial poultry pathogens i.e. Staphylococcus aureus, Clostridium perfringens type-A, Escherichia coli, Salmonella enterica, Haemophillus paragallinarum by using agar well diffusion method. Stock solutions of 0.1gm/1ml of all the extracts were prepared. Chloroform and ethanolic extracts of Gymnema sylvestre showed better antibacterial activity against all isolates of selected microorganisms, while hexane extract showed antibacterial activity against Salmonella enterica, Staphylococcus aureus, Haemophillus paragallinarum and Clostridium perfringens type-A, but no activity against Escherichia coli. On the other hand, aqueous extract showed antibacterial activity only against Clostridium perfringens type-A, while no activity against remaining four bacteria. MTT Assay was performed to evaluate in-vitro cytotoxicity of these extracts by using Vero cell line. Cell Survival Percentage was calculated. Results of MTT assay showed that 2900, 3612.50, 4075 and 1562.50µg/ml concentrations of hexane, chloroform, ethanol and aqueous extracts respectively had no cytotoxic effect. The antibacterial and MTT Assay suggested that sequential extracts of dried leaves of Gymnema sylvestre can be used as a safer antibacterial agent against the above bacteria. All results were compared statistically using DMR (Duncan’s Multiple Range) Post hoc test at P≤0.05 which showed that ZOI and MIC values were significantly varied between groups while there was no variation within same group.

Key words: Antibacterial, Cytotoxicity, Gymnema sylvestre R.Br., MIC, MTT Assay, Sequential leaf extracts, Well diffusion Method